Build Your Own SLA/SLS

Hi people,
I have built an FDM 3d printer but SLA is kinda new for me. Where do I get started for building one? like the mechanism used, all the calculations etc etc.
I do plan on building a good one for engineering purpose although I'm kinda lost on where to start (unlike open source fdm printing).
Any kind of information would be great!!!

this is a good place to start

Parts printed with current resin technology are not strong enough for engineering purpose though.

I have been going through some basics. I have some questions:
1. The frame: any advice on cheap and best buys.. i was thinking of Alu extrusions. But since there will be less moving components can I go with any other cheaper material?
2. The linear actuactor for vertical motion: Any ideas here again? THK KR26 looks like a good option. But if you guys have any ideas I can work on it.