They have disc brake conversion kits available. I believe cb performance makes something.
As for auto transmissions I really don't know anything about them. You could try it, but I'd keep it mild. These cars stock have like 30 or 40 hp I believe depending on the year. Some of the newer ones may have came with more than this. If I were you I'd check on like some kind of message board and ask what the safest engine size there is to run when you have an auto transmission. I'm guessing you should skip on the 78mm crank and stick to a stock counterweighted 69mm crank. Then get a set of the 94mm pistons. This will give you good power and put you up to 1.9 liters. You'll have to get aftermarket dual carb setup to feed enough fuel. I'd also recomend getting some aftermarket heads. go to http://www.mofoco.com I'd get them ported and polished if I were you. Take either the 041's or the 042 depending on what you can afford. But which ever you get I'd have them ported and polished. You'll also have to pay extra for the large bore since you'll have 94mm pistons which is $10 extra per head.
I can't believe how cheap parts are for these cars. Parts for my gutless saturn cost as much as performance parts. I didn't realize this when I had the car because I was a broke high school/junior college student so it seemed like a lot of money to me.
