Tight on money, 2 things... Do minor mods and work your way up slowly... or save to do something major. I've heard of going with the sohc set up. Its your choice your car. If you are worried about reliability, then just don't over do it. Plain and simple. Going the turbo route, means you just don't over do it. But I'm sure you can get the power that you are looking for.
That is my 2 cents...l8s man