hiya
Sound like an intersting project...couple of pointers below that may (or may not!!) help you out....
If you specify, when you order your paint, that you will be brushing, then most a paint schemes can have an additive put in the binder which allows it to flow out better loosing brush and roller marks. I know maxmeyer , alcea and lechler all do this....
With a view to matt paint....If do a NATO or cammo paint job I would use satin matt sooner than straight matt.
I have found that matt is much harder to clean when it gets muddy and your whole car feels like a sheet of p1200 wet n dry!!
Satin looks much the same only with a slight sheen to it...looks sweet and the dirt washes straight off!!!
Might have probs with applying cammo if rollering or brushin, as looks much better with fogged edges not hard...
easiest way is get a couple of litres of brushing in one colour and then paint the whole car, and get a couple of arsehole cans of your second colour and fog in your cammo when the 1st colour is dry.
The satin or matt first coat will give the second colour enough of a key so no need to scotch up between colours.
I wouldnt mask your cammo, just do it freehand so it fades in and it will look much better....sometimes less=more so add a bit at a time, and stepping back and keep adding more if, and only if, it is needed....
....and finally keep having a look from a distance when doing cammo to check your design....I did an urban cammo job on a scooby a few years ago and from a distance it looked like it had got "T1T" written down one side in 36" fogged writing!!!...appropriate maybe and rectified easy enough, but a tadge embarrassing seeing as I didn't even notice it!!
Just one more tip...if you want the designs the same on both sides......draw or print your design onto an clear acetate sheet, borrow or acquire an old overhead projector for a day and project the design onto the side of the car,then paint in or mask around, then flip the sheet move the ohp to the other side and repeat..really easy to do.
I bought 2 old ohp's off ebay for up my workshop for £15 the pair, on ebay, so not dear to do at all- saved me keep using my multimedia projector out of the front room, hooked up to my laptop..far too pricy to get covered in overspray and works just as well. Use them all the time for flaming...wickedly easy.
Hope this helps you
Gregster
does anyone here on the miricled off chance have any spraying equipment and somewhere to spray bit random i know but im planning on a respray and was hoping by sheer luck that someone here has those sort of fascilities and would be willing to let me use them for a small fee ill do all the prep and stuff at mine and providing your not too far drive there mask blast have take away and be out lol
remind me to buy you a beer 
