DPL & DPL II are old tech. yes they work, but as a wrote earlier, they kind of simulate surround sound. well, since the source signal itself is stereo, the sound-system will have to do that. but the feel wont be what you'd get in a true surround sound system. in the former, the sound-output will be a mish-mash, ie, all speakers would usually be outputting the same sound, with some emphasis in some channels (which gets better with audio-tracks like DTS or DTS-HD in movies), while in the latter, the sound gets out through different channels, ie, the sound meant for rear or surround speakers would come out of only the rear ones, & likewise.
in 20k category, better look at logitech z906, or even better, get an HTiB (home theatre in a box) from the likes of yamaha or onkyo, with which you'd get an AVR (audio video receiver, that houses an amplifier & board to accept audio-video inputs from multiple sources) & 5.1 speaker package, if you can spend around 25k. if no issues with getting a used one, then you can get for cheaper. a better alternative but in which you will have to patiently invest would be to get a good, used AVR first, & later on keep adding speakers & subwoofer to it.
in 10k category, there are several options...i'd suggest to chuck out a DVD-player (its irrelevant these days, unless ofc you dont have access to internet & online shopping)...look for standalone 5.1 systems, which you can pair with a TV or a PC or a media player or such.
attaching a bluetooth dongle should work. i have not used one, but feedback tell that it works.
PC connection through 3.5mm would reproduce worse sound. generally these systems have the provision of connection through RCA ports (white & red) at the back of the subwoofer. so you could use a 3.5mm to RCA cable for connection. but as i wrote, the sound output is not very impressive. would rather suggest to get a sound card like asus xonar dx, and then use its output ports to connect to the sub, if such a provision is there at the back.
am going to sell my edifier da5000 pro. had you been in Mumbai you could have taken it. its just the kind of under-10k system that you want (but minus BT), and a VERY musical 5.1 system at that!