What sizes, how may and what kind? I'm thinking nylon, are they good?

Flats: ?
Rounds: ?
Liners: ?
Striper: ?
Spotters: ?
Any other??

First notion is that brush are investments. The cheap brushes are just that - cheap. Spend a bit more and get better results.

The shapes - I would get Flats, and liners. I would get liners as small as possible. 0 -00 - 0000 at least.

Nylon, ehh, not sure, I'd try and stay natural.

Yep thy're investments..... The White Nylon tend to stain with darker colored paints. I do prefer the Natural ones over the nylon.

Thanks for input lads....what do you feel about sable hair brushes?

The Sable is one of the more Common ones.... (that's what a good chunk of mine are) With care & Proper cleaning they'll last years.

To protect the tip I keep the small dia Plastic Coffe stir's handy.......

Sable brushes are decent and worth the money.

The better your brushes the better the result. Good sable give good results, and if taken care of last a long time.
As for sizes and types it really depends on what you want to do with them.

I use Series 7 rounds from #1 down to 000 for details
Flats for ground work, and filberts for dry brushing. The flats aren't the most expensive, as they take a beating doing ground work, and dry brushing.

As already mentioned, you get what you pay for.

With flat brushes- Royal Taklon are not too expensive and quite good, for my use sizes 4, 6 & 8 are adequate.

For Synthetic Round brushes, Winsor & Newton Cotman III are good for water based paints. (sizes 4/0 & 3/0)

For Sable Round brushes Pro Arte Series 40 Crafters are pretty good, I also have a few Javis sable brushes which are cheaper, but still quite good quality. (sizes 3/0 to 0)

Sizes 1 to 3 are covered by, Humbrol, Revell and Heller (bought these at a Sale), they are okay (quite good actually) for the odd jobs.

Hope this helps

Thanks lads, you've been outmost helpful.....