Just a thought sds..
Since you will have some nice thermal protections built into the unit why not use a CPU style heatsink?
To me it would seem big heatsink for less protected setup and small heatsink for well protected setup. Would save you lots of space and weight and make for a cleaner build.
I like big heatsinks too...but if I had those thermal protections in place I'd run smaller heatsinks.
Nice build design so far, you have definitely got me interested in arduino now. Not sure I've got the time to learn something new like that...was thinking of getting the spark fun learner kit...think that would be enough to teach me how to build and program one?
I thought about the idea of smaller heatsinks ,from other 'space' ..
(Computer World,Audio World ,etc ....)
Still I like those ..monsters ....
Two words ...
' HIGH - END '
..
'FREAK' ..<=.....that's me underneath those two words ..The third one ...
Before you buy/purchase ANYTHING ...
Read ..Search and study on the web ,info about your project ...
Learn..Educate self ....(it saves money ,trust me ...)
And then you can put your hand in the pocket ,to reach for the wallet ...
But,first...Search and get to know as best as possible what exactly you do need ...
I do not believe in 'learner/newbie kits '..Always over-priced for the uninformed ,innocent ,enthousiastic victims..
Get a simple Arduino Uno ,a relay break board ,1 & 10 K resistors ,10n,100n,47uF & 220UF caps ,some BC547 transistors and an LCD display ...and some epoxy small leds ..And a button and a toggle switch ....
Enough to make first moves in the microcontroller's world ....
^^^That one 's a beauty ! Pure Copper ,six oil filled heat-pipes ,massive base with added fins..
Hard-Core ! Active ( 90 mm Fan ,6500 rpm ) it used to handle ~180 Watts of heat,with ease ...