I have seen guys do really well on 250mg test per week. 500mg is not a big cycle though. Figire that 250mg EW is close to being a hormone replacement dose. You can always try it though and see how you do, then go up in your next cycle. It'll take several weeks to kick in, so if you think you'd like to do more, you won't really know until the cycle is half over. At that point, adding more would take another several weeks to kick in completely. A middle ground may be to use 375mg per week for the first run.
And yes, you want to use adex for estrogen control on cycle for estrogen control. Then still do a PCT after using Clomid.