Most of us use examples from experience so I will do the same

Some passive bookshelf speaker ideas:
I have a pair of the Ascend Acoustics Sierra-1s (actually L/C/R) that I've enjoyed a lot and the current sales price is pretty good
http://www.ascendacoustics.com/pages/products/speakers/SRM1/srm1.html altho if you can bump up your budget to $1500 or so the Sierra-2 or Sierra-2 EX look pretty nice too.
Since you built some speakers before, I've also built this kit and they're quite nice (and were the basis for one series of Dennis Murphy's Affordable Accuracy speakers when he had Philharmonic Audio going)
https://www.parts-express.com/dayton-audio-br-1-6-1-2-2-way-bookshelf-monitor-speaker-kit-pair--300-640
I also have some JBL 530s, altho I've never used them as mains, several others here have, unfortunately a recent sale is over at which they were an especially good bargain.
For active speakers I have some JBL 305s, which I consider a great bargain as well. I'd really like to try the 705s, but they're a bit pricier.
What is the pair you and your dad built?