The brands you suggest are spot on - I use Brooks Adrenaline GTS 10 for long runs, Asics Noosa Tri 25th for short ones (up to 10k) both with locklaces in them, 2XU trishorts, 2XU tri top, 2XU compression calves, arm and leg warmers from Decathlon, nice soft baseball style hat for the run (INOV8 summer cooler). I use separate shorts and top rather than a trisuit for a tri as I get too hot in the pool in a trisuit, and too hot under my wetsuit in open water. I've also used tri shorts with a cycle top for a tri with a longer bike in it so I can have gels or bars in the pockets ready to put on after the swim. Best prices for 2XU stuff I could find was at Ribble cycles online.
However I have run gear from More Mile (from startfitness.co.uk) and it's top! Great prices too. They also do trisuits, tri tops, tri shorts and their own locking laces which work well. I've just got a tri top from them, but haven't tried it in anger yet so can't comment.