I don't have a Seekins bolt rifle, but their website states the Havak action is compatible with R700 stocks & triggers (i.e. has the same footprint). The bolt release doesn't look to be above stockline & it has a straight bolt handle (so do many R700 clones). I don't know the length of the ejection port, but you could call Seekins and ask.
I think the question is: do you want the action to look like it grew out of the stock? If so, you probably want a flat top that gets inletted specifically for the Seekins. Otherwise, If I were in your shoes, I'd probably order the Clymr with a Defiance Deviant inlet to be close on the bolt release, port will be pretty close, and bolt handle will be close. I'd take a piece of sandpaper & in 5 minutes the Clymr would fit. I'd also take 10 minutes to call Seekins and Gunwerks to confirm there's nothing else to look out for.