First off, tell him welcome to the joys of wakeboarding. that is great that the two of you will be able to board together and build off each others vibes.
If there is any further info you can give about what your bro might like that would be helpful. at this point the sky is the limit on suggestions. but i feel for ya and him on this. it is so hard to decide when your new in the game, let alone with minimal demos. sometimes the best question is to ask oneself is "what style do I want to develop" when one has had a lack of time to gain experience.
some things to ponder:
1.)Try to narrow down rocker type desired
If your brother would like more speed than go with a rocker pattern that is not 3 stage the severance and era are both 3 stage boards (though i think the erra is a mellow 3 stage, "blended 3 stage")
If he is ok on the speed then stay with 3 stage and hybrid rockers
also remember that 3 stage tends to "buck more" for a steep trajectory through the air and continuous rocker provides a smoother kick and arc through the air.
2.)flex or no flex
Are there any other things that your bro likes about the severance besides the soft landings and butteriness? does he like the general feel or use the flex when sliding around? if not then maybe flex is not for him and he can get the benefits of a loose board and soft landings other ways, such as a board with simple bottom features and concaves/spines through the belly.
check out the toys for tots auction for deals if you have not already
http://www.wakeworld.com/news/featur...er.html?page=2
there is a package deal on a CWB faction setup with boots. continuous rocker board. huge long center spine for soft landings for your bro. very simple bottom like the severance (besides the spine) that will make it feel loose like the severance.
cwb vibe that is a flex board with a mellow subtle 3 stage rocker that out to ride much like the severance
Hyperlite Marek, continuous rocker. supposedly a very fast board. also has a bit of a spine in the center. i think this board will be the grippiest of the boards on the auction and not as friendly as the others at buttering around at least untill getting very accustomed to the board
obrien Decade, 3 stage, fairly simple bottom features, besides the delta chevrons which are designed to speed up the board. nice v bottom for soft landings.
the other boards listed i think might be too small... judging from your profile saying that you have a 142 era
f.y.i./ disclaimer: I have not tried any of the above boards, just spouting thoughts based on the boards' designs and other peoples' opinions that i have heard.