There are warranty implications regardless of the cam you use. While the installing dealer may cover it with the SE cam the MOCO and other dealers will not. Take the bike to a different dealer or a good indy shop to do the work and get the cam instaled that you want.

What he said.
I get so tired of hearing this kind of misleading crap from dealerships that I want to scream. First and foremost, don't just accept some verbal BS that they will cover it if you have them do the work and use the parts they tell you to use. If they don't put it in writing, it's total BS. They, and they alone, will have to cover any repairs because as Jim just mentioned, H-D or other dealerships will
not honor the factory warranty on a modified engine, no matter what brand of parts are used.
There is no SE cam in the catalog that is really close to the specs of the TW-7, the closest is the SE-259E.
TW-7 Lift: .575" Duration: 240/240 Timing: Int 20/40 Exh 42/18 Lift @ TDC: Int .194" Exh .176"
SE-259E Lift: .579" Duration: 246/250 Timing: Int 19/47 Exh 58/12 Lift @ TDC: Int .182" Exh .155"
If you've determined that the TW-7 is what you want, stick to your guns. It shouldn't make any difference to the dealership which cam they sell you, they make good money on either one, so the insistence on using SE parts makes no sense at all. If they don't see it that way, or won't give you the "warranty" statement in writing, you need to move on and find an honest place to do business.
Jerry