Nice tank!
Get yourself a sump and make a couple of DIY Durso standpipes to put in the overflow boxes (if they aren't there already). You can put your heaters in the overflow boxes or in the sump so that they are hidden and will not get broken by your large fish.
Do some research about sumps to see how they work... they aren't too tricky... you may just want to make one and save yourself some money.