Normally sells for around 100-00 for 78-00 quid, bargain...
http://www.toolbaydirect.co.uk/cata...tion-Soft-Grip-Air-Sander-Kit-5229PRO/174225/
if you want a sander and polisher my advice would be to buy a sander and a polisher the sanders i have seen spin too fast for polishing with compound even if you were to turn down the air pressure you lose some of the power look at bodyshop machines they also have foam heads available in different grades too fast and the friction burns the paint.
As above, less that 2000 rpm for a polisher, sanders are faster than that. My mate has a mini air polisher, I think it's a "Chicago" one. A fair bit of money - around £80 or something. Nice little thing though.
this one I think (though link is to a US shop)
http://www.toolprofessional.net/Chicago-Pneumatic-CPT7201P-Mini-Polisher-Kit/M/B0002SRNNM.htm
Last one is a sander, 15k rpm, way too fast for polishing. You want sub-2k rpms, probably run something like 1800 max really and often a lot slower. (That said I mostly do my bike bits by hand so someone else will have a better idea of rpm's)
2k, polish within a hours/next day, after that it gets damn hard...
Paint seems much harder after a day, daresay the pro's have a way but as an 'umble garage bodger it seems much easier to do next dayish / lot more difficult later than that esp with straight colours
I have a Kestral DAS6 polisher/sander. I got mine from http://www.cleanyourcar.co.uk/
Excellent service from them every time, and the Kestral has never let me down. You can now get a "pro" version with a more powerful 800w motor (I think). I have the original and it's never let me down. Cost about £85 + delivery.
Just buy the appropriate sized backing plate and sanding discs, then off you go. If using for polishing, then same applies, get the right backing plate (comes with a 125mm (5 inch) one I think) and pads to match, then off you go.
EDIT: oops, never noticed you said air powered!
75mm though.