I am finding that my wet/dry setup is quite low maintanance too. Apart from water changes (10% every 2-3 weeks, which is prob more than needed as my NO3
never get past 5), I didn't have to do anything to the filter for well over 3 months now, no cleaning, nothing. Everything still looks great & the water is crystal clear.
Just make sure the overflow & sump water levels are set correctly, so you won't have to worry about flooding if the siphons/pump quit, or things get clogged, etc. <Actually, even though I worry about all the plumbling clogging, I have not noticed any build up any where, even at the distribution plate/pipes with all the tiny holes, things seems to break down quickly in my system & clogging is so far a non-issue.>
As far as buying advice, I don't have much, since I made mine (the ready made wet/drys are waaay too expensive in town - like $300 & up). I did do some research on pumps & the ehiem & mag-drives seems to be good. Also check the product review at this site here:
Unless you are drilling your tank, I would suggest getting an oversized overflow for your intended flow rate:
1. less risk of flooding - should anything get caught in the overflow.
2. less noise - the overflow can be very noisy ... best way to quieten noise is with a durso standpipe (cuts my overflow noise by 99%), but that requires BIG pipes to work well (like 1.25" & up), so you want to have enough space.
3. you can upgrade with a better pump down the road.
I also have 2 siphons in case one quits .... well maybe I am just paranoid?! 8O