Intermatic makes subpanel/timer housing combinations; something like this: http://www.poolplaza.com/P-INT-30-698-T.html.
Intermatic makes subpanel/timer housing combinations; something like this: http://www.poolplaza.com/P-INT-30-698-T.html.
Intermatic makes a pool panel with a space for two timers in it. I have exactly the same set up you have. If you have a heat pump get the larger capacity one since the heat pump can draw quite a few amps. This pool panel also has a breaker array in the cabinet where you can put all the breakers for your pool. It's a great panel and does not cost a fortune.
I assume your electrician checked, but make sure the lines feeding the subpanel are the right size to handle the added load of the heat pump. I don't claim to be an electrician, but the code book has pretty straightforward rules regarding voltage/amp load/wire gauge/distance. 90A on the existing one sounds big. You may have a 50A and 2 20A breakers in the subpanel but that does not mean the load is that high. Check the breaker at the main panel.
You could use a Goldline PS-4 it comes with a breaker box and you can set run times on your pool pump and your cleaner pump. Then down the line you can add a salt system and an in house control pad. www.haywardnet.com/products/displayProd_controls.cfm?ProductID=124