I'd definitely just mix acrylic paint and latex. I've used it myself just fine. You can also use PAX which is acrylic paint mixed with pros-aide, seems to be industry standard.
I'd avoid using the house paint if only for the fact that you might not know exactly what it contains, and anything that contains oils will eat latex. Got to be really careful with natural rubber.
I know the feeling - I'm in an Aussie state capital but even so getting cheap latex is almost impossible! I get mine online too
See if you can get pros-aide for a decent price though, I keep hearing it's the best for painting latex when used to make PAX paint.
ok so what I used was latex, distilled water, and acrylic paint...I watched loads of video and read tons of forums and this formula seems to work for me. Plus, it's pretty cheap! lol and I can get it all within 50 mile radius...lol
but heres a picture...