Hello Muzamil
I would if I were you spend a bit of time researching the Sinar cameras before rushing into a purchase. Dave Tolcher started a topic with some links to some usefull information on Sinar cameras and others I have added a few more links to Sinar information you will probably find usefull.
viewtopic.php?f=3&t=2951&p=17534#p17534
Very basically Sinar Normas are the older cameras made from 1947 till 1970 when they were replaced with the Sinar P this itself was superseeded by the P2 in 1984 The Sinar F is a field monorail camera introduced in the 70's and replaced in 1986 with the newer F1 and F2
Sinar normas are all metal monorail cameras but are not a yaw free design and do not have geared movements exce[pt on the focus
The Sinar P has yaw free tilts and has all geared movements the major difference with the P2 is that it is black rather than silver in colour and the swing and tilt are controlled by seperate knobs on the P a lever selects which function the one knob does.
The sinar F is a simplified field camera that still has yaw free tilts it only has geared movements on the rear focussing standard
Sinar C's are a combination of a Sinar P rear standard with an F front standard
The F1 is a more robust F and the F2 adds geared foccussing on both standards
The X is a cut down P2 where you can not change the format size
just about any bit of sinar camera will work with any other bit as they are modular you can use say a norma back on the later P2 standards, there are a few important exceptions to this compatability which i will try and cover.
With the P or P2 cameras the format can be changed to 5x7 or 10x8 by changing the bellows rear carrier frame and back ...more info on this in a bit
Changing format on the Sinar Norma or the F range of cameras involves changing the entire rear standard and back and bellows note that on the F2 the genuine front standard for 5x7 and 10x8 is a much heavier duty item from the 5x4 one.
The main compatability issues are with the 10x8 bellows with the 5x4 and 5x7 bellows there should be largely no issues some minor exceptions to do with norma belows with the front plate with the round hole for 5x4. The issues to do with 10x8 are to do with metering backs for a long time Sinar has offered film plane metering probes and matching metering backs all the 5x4 and 5x7 backs and bellows are compatable with any era not so the 10x8 here the metering back is considerably larger meaning the back and bellows and carrier frame are different too as well as accessories that fit in to the back ie reducing plates.
Norma 10x8 bellows will fit a P and vice versa but the norma bellows are a better fit on either and some complain of p bellows falling out of normas.
With the 10x8 P or P2 be aware that because of the modular nature of the cameras people often brougfht 10x8 conversion kits the from factory 10x8 cameras that are 10x8 have "specail" heavy duty standard bearers where the index marks are set up for 10x8 the rear bearer is much more massive and the front has much greater rise.
Sinar have over the years made a variety of behind the lens shutters the Copal auto shutter the longest running of these these are an imensley usefull accessory 1: if its your thing it makes using odd lenses easy 2: sinar marketed a large number of lenses to match the shutter without there own shutters these can often be found for greatly reduced prices compared to the shuttered versions ... the disadvantage if the auto shutter plays up you are stuffed. If you go for an auto shutter the cable release is specail to it and must be in good condition if the plunger rod is sllightly bent it will cause you knightmares the auto cable and the matching screw in for the backs is not essentail but if you want to use flash the syncro cable is.
Avoid the digitail shutter untill you know you really want want and are prepared for the potentail grief same goes for the later Expolux shutters.
You can get started cheaply with a variety of F and still use all its bits later if you upgrade, or look into things and possibly a P or P2 10x8 will be a better buy as it will do all you want.
If you are tempted by the film plane metering go for the Sinar boster 1 and the Minolta Flash Meter IV this with a few exceptions is more practical / robust that the other solutions offered over the years
all right then it has a smaller metering area and a longer rod than the earlier probes so can cover 10x8 the earlier ones do not fully do that the main length of the probe is metal the earlier ones are plastic I have seen people suggest the earlier ones are more robust this is not my experience. the FCM booster works with the Broncolour FCM meter but its range is only really suitable for Flash. The earlier Proffiselect TTL has a higher sensitivity than the Booster 1 but is a lot more fragile in my opinion.
This is posibly more than you needed / wanted to know but hopefully sumarises some of what you can do with the Siinar System.
then again you may find a completely diferent range of cameras suites you.