Welcome to tsikot! As per your indash, average price range of an in-dash unit (JVC/Kenwood/Pioneer) would be around 20-40K. For the Spark, I think mas maganda kung all-in-one na ung bibilhin mo, meaning integrated na ung in-dash, dvd, cd, mp3, at radio functions.
Stock radio ng spark I believe is 1 DIN ung size (almost just about 1.5 inches ang height), so you should buy a 1 DIN HU na in-dash din. If youre tight on budget and you can live with a just-average sound quality, you may try this (link courtesy of ebay.ph):
http://cgi.ebay.ph/1-DIN-TV-Tuner-Bl...QQcmdZViewItem
Gave one as a gift for a cousin who wants to watch TV on his old Toyota Corolla, well, he got more than what he wanted.

Still working up to now, inupgrade niya ung speakers nya plus nagpalagay sya ng sub and sound improved more. ;)
By the way, there are many more of those generic multi-format 1-DIN player out there, meron pa ung talagang 7 inches ung screen at motorized pa. Just look over the net, marami yan. Mismong dito sa Tsikot Virtual Banawe meron.
