Aggreed with Tido.
If you got more room and money better go for the biggest tank you can house.
That will keep you from having to upgrade again.
Secondhand sites are excelent to find a complete tank.
I bought mine secondhand.
I payed 500 Euros for the complete 180Gl setup with sump, pumps, lights, nightlights, heaters etc.
Keep checking those sites and a good deal may come your way.
Mind you i found my tank in the city i live.
I got a good deal, because the guy had to move and could not take the tank.
Good luck!