There is nothing wrong with wanting a manual, but some of the autos are pretty nice. I used to be a manual die hard but after a while I began to see the attraction of 1 less pedal.
Both C30s and S40s are great little cars. The S40 is roomier in the back than you might expect but there is very little boot space.
There is a wealth of information out there between ozvolvo, volvoforums.co.uk, swedespeed, and (to a lesser extent) t5d5.
Out of the C30s I would very much go for the manual over the automatic. C30s came with either the old AW55 5 speed or a Ford dual clutch PowerShi(f)t 6 speed, both of which have had their fair share of issues. The manuals in almost all Volvos are pretty problem free to my knowledge. The base LE (4 cyl petrol) and better S models (5 cyl petrol) came with a 5 speed, T4 and T5 (turbo charged) got the 6.
The S40 also came with the quite nice TF80 6 speed auto which from some time in 2007 onwards has been very reliable as long as people don't put the wrong oil in them. 2006 and prior can have valve body issues, though, so I would avoid them. The TF80 is still sold in Volvos today and was quite class leading back in the mid naughties. Fitted to a lot of cars including Ford, bmw, and Mazda.
AWD is the choice of revheads, but is not available with mabuals. The FWD is also quite capable in the dry and will be a lot lighter with better fuel economy. You will get traction issues if you like the loud pedal but they apparently stay fairly composed when things get slippery.
Combined with the turbo T5 and you can have a lot of fun through the twisty stuff. The D5 is pretty reliable and capable, but as with most active regeneration DPF diesels it won't take well to inner city driving. You probably won't get one in your budget regardless.
Edit: Pickings are a bit slim for manuals at the moment, C30 S with low km in NSW
http://carsales.mobi/cars/details/2010-Volvo-C30-S-No-Series/OAG-AD-12795835
C30 T5 with more km (but more power and the 6 speed) in QLD
http://carsales.mobi/cars/details/2010-Volvo-C30-T5-No-Series/OAG-AD-13019477
There's been some C30s going very cheap recently so be aware that they probably won't hold their value well as the km climb higher.