The Intex Ultra pools run to 52" (3' 9" of water) and seem to last 5+ years with care. Some of them are available with sand filters, like this one
Intex 24-Foot by 12-Foot by 52-Inch Rectangular Ultra Frame Pool
Plus, if you upgrade further within a year or two, you can probably Craigslist the pool for 1/2 of what you pay!