Basically what I want is a mod that adds a new house in IC (the waterfront one just isn't working for my noble character). However, I can't find any that don't conflict with better cities. Any help is appreciated.

You don't like the old shack, eh?
Add http://http://www.tesnexus.com/downloads/file.php?id=2556 and you'll change your mind.

While I appreciate your help, you'll understand when I say that this is not what I'm looking for.

If you don't mind a short walk (the house is outside the gates but easily reached), you might like http://planetelderscrolls.gamespy.com/View.php?view=oblivionmods.detail&id=3834. It's not a castle, but it's a quite nice place (and far better than a shack).

Wow man that's exactly what I'm looking for. Thanks a bunch!

Princess Stomper's http://planetelderscrolls.gamespy.com/View.php?view=OblivionMods.Detail&id=2534 should be fully compatible with Better Cities.
Also http://www.tesnexus.com/downloads/file.php?id=16611 should be compatible, since I assisted the modder to help make it compatible with BC (plus made a couple of adjustments in BC Arboretum to ensure compatibility too).

Ok guys thanks for all the replies you guys rock!

This isnt quite what you requested, but it is my favorite house mod so thought id throw it in here in case you hadnt considered something like this

basically it adds an amulet that you buy at rindirs staffs, when you equip it it adds a spell to summon a portal which, when activated, teleports you to a small home, the spell can be used anywhere and costs no mana, and when you leave the house it teleports you right back to where you cast the spell

http://www.tesnexus.com/downloads/file.php?id=20099

Here's another thread with a few more suggestions: http://www.gamesas.com/index.php?/topic/1077056-market-district-house-for-sale/page__p__15676499__fromsearch__1&#entry15676499