Well, you may want to say what your budget is fella.
I can recommend the obvious.
Electro - Smart parts ion/vibe/XE , SP1, PMR - they are cheap to buy, are reliable and easy to maintain.
Mech - Tippman A5 or X7 - More of a milsim look, reliable and tough as nails
All of what i have suggested will retail for less than £250 ions and PMR's are the cheaper options at less than £120
And if you hang around in the classifieds, you are likely to snap up a real bargain
As for places to play check UKPSF website here:
http://www.ukpsf.com/ or other woods or recball affiliated companies such as Go ballistic. Ask around many sites do walk on days where you can take your brand new marker and just pay for green fee and paint.
Best of luck fella!