It sort of depends on what the scenario of your home is - We just moved into our first home, have been doing apartment living for the last five years, and just recently (January this year) bought a DT25.
It's loud, like, really loud. You can play it in low volume mode. You can also just plug the 1/4" from the HD500 out to the back of the DT25, into the FX return. That will allow you to use the HD500 in studio/direct mode. In terms of recording, if you have a computer, you have all that you need. Plug the current headphones or speakers into the audio out of the POD, connect the USB cable to your computer, and load some recording software. It's not like you need to go spend $700 on Pro Tools 11; there are free audio recording programs. The POD is the soundcard, and does a fine job with the ASIO drivers.
I actually just bought some L2t's, which should arrive today or early next week, so I am pysched to jam in the (finished, carpeted) basement at the new home. It's pretty hard to properly use a 25watt Bogner/Line6 tube amp when you live upstairs, and have downstairs neighbors!
In terms of home monitors, there are a plethora of options; I was very recently comparing prices and brands - KRK, M-Audio, JBL, there are several 'budget friendly' options, in the $300 to $700 / pair price point. Those type of 5" and 8" woofer, powered two way monitors are usually priced 'each', so for example the KRK Rokit 8" G3 is $250/each, the KRK 6" G3 Rokit is $150/ea.
JBL LSR308 (8") is $250/ea, supposed to be pretty nice. LSR306 is the 6" version, $150/ea
M-Audio has two way and a three way models, different look in the three ways, both sets in 6" and 8".
The two ways, (Carbon) BX8, BX6- are the $150 / $250 price point, the three ways are M3-6 and M3-8, which go for $250 and $350/ea, respectively.
For the most part, any of these kind of powered, semi full range, mostly flat response speakers will perform well with the HD500.
If you can crank up the volume at home though, and your budget can withstand the G.A.S., definitely take a closer look at the 1x10" L2m/t and/or the DT25. They are two very different approaches to interfacing with the HD500.
The L2/L3 are true full range / flat response. The DT amps are really a Bogner tube amp with the Line6 modelling interface. The manner in which the HD500 "talks" to the DT25 is really quite amazing, and you need to be able to play at more substantial volumes to really appreciate what it can do. The HD modelling on it's own is great, but it does come to life in a unique way with the DT gear.