This level is getting better and better! I'm really looking forward to when you finally release it! 
As for houses, or tilesets in general, I don't know how good I am at drawing them, but I've just done a saloon (heavily inspired by this picture: http://www.kolpingjugend-peissenberg.de/Reports/Images/saloon.gif), and if I can help in any way (be it good or bad, or just with one single saloon 
), I'll try because I'd hate to see this project abandoned! So, well, have a look at the attachment...
...
That's amazing! But, unfortunately, I can't use it because I told Purple Pineapple he could do it. 
But it seriously looks a-freakin'-mazing. 
EDIT: You can probably make a tileset yourself. Just make sure to put transparency in. It's either pure black (RGB 0,0,0) or magenta (RGB 255,0,255)
That's okay! I just took this as a sort of inspiration to draw something - at first, I didn't even draw it with the primary intention of uploading it so no bad feelings there
I also realise that strictly speaking, it's not even isometrically correct - just have a close look at the planks (is that the right word?) on the floor in front of the windows; but I suppose that's a general problem when trying to introduce perspective into pixel art... But it's not as evident now as it is at 800% zoom, I can tell you...
If you like it anyway (I'd be honoured if you did), I would be okay with Purple Pineapple integrating it into his/her tileset (if he/she is okay with that too); I wouldn't even insist on being credited, just feel free to use it any way you like
I could also make a tileset if you want me to, just tell me what kind of tileset you'd need - but it would be my first real tileset so you shouldn't rely on me alone
And I ought to warn you that I'd only be able to work rather slowly because I have to move in April and there's so much to do for university... But if I can shorten the waiting time for the level a little by contributing
something (even if it would just be an unfinished tileset) that would be nice
By the way, I use GIMP, which has "real" transparency - would you be able to work with that as well? (In fact, I think I used pure black for the borders of my saloon - I could paint them over with (1,1,1) though.)