would i be stupid if i replaces micro unit with pico?

[FixupSellon]

my e350 apu came in a custom unbranded micro atx slim line style case, now im debating what to do with it, downgrade the case just big enough for a 3.5 hdd or sell it as it came and buy something different, something already in a smaller case or better unit all together..

now, ive test fitted a micro atx board in the case as i was swapping the boards round for trials and while it fitted perfect the psu could not be fitted as while its a micro its also square and the design of it all means theres a cattle like lead inside the case from front to back as the unit up front under hdd/optical caddy, so ive discovered i would either need a smaller or long slim psu that fits the hole points or get a slimmer micro atx board which i dont know how limited they are or do this pico thing i thought about earlier..

pico i was looking at was 160w, the micro atx unit is 300w, the system as it stands only uses hdd, optical and i have 5gb ddr3 ram fitted(board(mini itx) only has single pci slot and i dont need to use it), if i fit a new board then depending on graphics i probably still wouldnt use any expansions.


so yeah is my logic good or are there better options im not thinking of?