strange you had such a hard time finding a cheap tank. here in pa people give them away for free since its so hard to scrap them. very large tank btw. i would not wanna plant that entire tank the way it sits, plus how would you ever find your frogs?(assuming you go with thumnails because of the high vertical)
my opinion is get that crack fixed and split the tank; establishing one half first. do what you feel though. would be a good start
good luck my friend