I would recommend a Sigma AV7000 supergun with a Sigma TB9000 joystick. The entire rig is pretty expensive though - at least $400 + shipping.
This is what I use, and I would not want to use anything else. Superguns can be as cheap as $100 (some even cheaper if you make it yourself), but you
get what you pay for.
Once you have a supergun (and a TV or RGB-compatible monitor) you just need a DDPDFK 1.5 PCB. These run around 120,000 yen at JP shops at the moment. The last bare PCB sold for 83,000 yen on Yahoo Japan Auctions (the last complete kit sold for 90,000 yen), so this is a cheaper route (though you have to deal with a bidding service middleman and all that). It should drop some more in price over the next few months, but don't expect it to go below 65,000~70,000 yen unless there is a port announced. It looks to be patterning the same as Futari 1.5, in terms of price.
So you will likely need at least $1000~$1500 to play DDPDFK 1.5 at home.
