I'm trying to find the best candidate for my Toshiba Satellite l450-12e with a Intel® Pentium T4300 processor, Mobile Intel® GMA 4500M graphics card. I have 4GB RAM and a 500GB disk. I'm going to develop on this machine, so I need it functioning with Snow Leopard or Lion.
I don't think I must have accelerated graphics, but some kind of network connection is a must, preferably wireless.

Could you suggest some likely paths to get OS X installed on this machine? I'm willing to purchase Lion or SL. But perhaps I'd like to try anything that works first.

What are my options? What should I investigate?