if i were you, i'd get a cheap used mainboard with CPU. and power supply. things that nobody wants, an older generation architecture. and slap in an ATi HD5450. and waste all the rest of the budget on storage and HT and display.

i bought my Core 2 + mainboard for RM325, Silverstone ST56 (considered as mid high if not high end) for RM150 and ATI HD5450 for RM165.

the grandia gd05 is nice and big

LC17

i'm using LC17. the 2 X 80mm rear fans are moved to the front blowing fresh air towards the hdd. will be adding another 2 more fans blowing to another set of hdd.
plenty of ventilation space for an average user, which would probably won't require any additional mods (or fans). the 2 80mm fans are dead silent. more silent than your average ceiling fan.

cable management relies on how you arrange the cables.
yes it'll fit an ATX mainboard without being too cramped.
that xingmatek is using 12cm fans. which could possible block the cover. the lc17 have enough space to clear a normal atx psu. maybe it'll clear the xingmatek. or even if it doesn't clear it, its only by a small margin.

How about change your player instead of vlc ? I think that will have much better in cpu usage and the smoothness too. Any recommend player here ?