That's your primary hurdle. No digital inputs means not much in the way of compatibility. Budget is problem #2.
My initial thought, not knowing which precise PC make/model you own, is to encourage you to obtain some sort of media streamer box to send along content to. Might be tricky though, if you do not have video output on the PC graphics card, or because most streamer boxes now work mostly with HDMI output and not old school analog video connections. Question: could you dual boot w/ Windows 7/8 since I don't know how well media streamers play w/ Linux(?) [Another good reason to not abandon windows entirely is for device/multimedia compatibility purposes. YMMV. ]
For now I would stick with audio, since you could find a refurbished media streamer like a Roku or WDTV Live that can handle audio streaming via DLNA (at least the WDTV Live can). Not sure if your original iPad Mini can do this however. The newer (hardware) versions running iOS 6/7/8can though. Ditto for Airplay, if you wanted to go that route. Apple hardware/software dependent.
My gut feeling says you may want to look into HTPC-type software on the Linux side. It's nearly plug and play on the Windows side now though.
http://linuxlookup.com/guide_to_building_an_open_source_htpc_media_center_on_ubuntu
Hello! I have a very specific question. I have the following supplies:
1. A computer with WiFi, USB, and all that stuff running Ubuntu 14.04 LTS w/ Pandora - No Bluetooth
2. An original iPad mini w/ Pandora/iTunes Radio and all that stuff.
3. A two-speaker stereo with aux-in
4. Another two-speaker stereo with a lot of RCA-in/out ports
5. Multiple sets of headphones
6. An extra (old carthode-ray) tv
7. Virtually unlimited wires
8. A power bar
9. a budget of $0-40
Now, I want to make the most convinient streaming and even to a certain extent, video set-up possible. This includes the possibility of a 'front-row' esque program. I would need it to have Wi-Fi. Bluetooth would be cool.
Apologies for grammar/english errors, thank you for any suggestions.

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