@Greg my diy version looks like a house with solar panels on it, so not too portable ;)
I'd skip the inverter unless you're running something that demands AC power. (And if you are much, this 100 watt system is likely undersized.) Get a vehicle adapter for laptops, that is more efficient than converting to AC.
@Greg I also have a very small portable system, a 1 foot square panel (17 watts iirc) with a lion battery and usb and laptop ports. Light enough for backpacking and it's charged a whole family's gadgets including laptops when camping in sunny summer conditions.