Your Tyan is a Socket 370, of course. For it I'd get a Golden Orb for a FC-PGA and be happy.
Speaking in general, though, both types are ''easy'' to cool in that there are good HSF combos available for both types from Alpha, Global Win, Golden Orb, etc. The effectiveness of the cooling and which HSF's you can use depends on the layout of the board and the location of the CPU, surrounding capacitors, etc., and whether you're using a slocket adapter or not. The problem is that some boards are more ''crowded'' than others with respect to the ability to physically accept larger HSF's. And some of the better HSF's, like many Alphas, are quite big - that's why they're effective. Often the HSF will fit but will block one or more DIMM's that you might or might not need, especially with a Slot 1 board.
In the end it's probably a draw, but the FC-PGA is the new standard.