I haven't read others' comments, but wanted to weigh in on your querry.
Personally, I think that throwing the party yourself is much more appropriate than asking or even hinting around for one thrown by someone else. Showers were begun to help first time parents get going on all the 'stuff' that we're supposed to have for kiddos. To ask for a party for the presents and to ask for a shower (specifically) IS against the etiquite of the thing.
However, since you say you don't care about the presents part of it, I would recommend throwing some sort of little party, lunch, BBQ, or something once the little guy is here to introduce him to those you care about. You could call it a "Welcome ____ to the world BBQ (party, lunch, or whatever)" and specify in the invitation that presents are not expected.
Based on the manners and reasons for showers, it is wrong to ask for or expect one after your first child's birth. If someone were to throw it just because, well... that's their choice and it's your choice to accept or refuse.
Of course, this is all JMHO.