If you decide on Speedmasters you better plan on having the rocker shafts stands looked at, and the valve heights checked. If those areas have been corrected by Speedmaster that's great. Both sets of SB SpeedMaster heads I've bought in the recent past the stands radius did not match the shaft radius. The valve stem heights were all over the place as well and if you plan on installing oem style non-adjustable rocker arms you best check hydraulic lifter preload. Might be ok, but you need that checked over. And inspect all the heli-coil inserts. I found a couple on one head that were suspect, the coils were not fully engaged with the threads in the aluminum, slightly bent inwards/tighter coil at their ends where a bolt/stud is first threaded in. Not a major issue, easily corrected but rather shoddy IMO.
Now as to the Trick Flow heads? All you really have to do is make sure they are clean, test fit your components and bolt them on. They are that good. I have a set and they are on a running engine. I looked them over, removed/checked a few valves , valve job heights etc. because I can be anal. Verified, they are true OOTB for most mortals and applications. You buy them as a true bolt-on item, that's what you are paying for. But by all means if you just don't trust anything or want absolute peace of mind take them to a high quality highly regarded shop to be looked over. Verify that the technician(s) doing the inspecting is/are well versed in aftermarket performance heads, on par with the level of people assembling them at Trick Flow. Shops that know their sh*t.