You don't say what class you are looking to use the ESC for but currently i run the following in 2wd (dont be put off by the fact its 60A - this system is seriously quick indoor and outdoor with the 930 stock software with boost and turbo - never gets hot either)
http://www.rccarshop.co.uk/index.php...stock-esc.html
http://www.rccarshop.co.uk/index.php...comp-8-5t.html
For 4wd I use the 90A ESC with same software. 15 boost and turbo and its very fast.
http://www.rccarshop.co.uk/index.php...-90a-blue.html
http://www.rccarshop.co.uk/index.php...comp-6-5t.html
The box makes it easier to update and programme the ESC using the downloadable software. Either system with the box is around £100 and I personally think its great value for money. Been running hobby wing for 4 years now and they never miss a beat. You can then spend £50 on other items to make you go faster
http://www.rccarshop.co.uk/index.php...ogram-box.html