Yes the PS1 version is not graphically as advanced as the PS2 version but it makes up for it with the sheer number of battles.
Unfortunately there are three versions. Panzer Front (Orig) Panzer Front Bis (Japanese super version) More battles and a fully functioning mission builder. This is the one you want to get your hands on! But it was released in Japan only so it would have to play on a Japanese PS1 Or CPU PSX emulator as I do.
http://thepanzerfront.yuku.com/ <--is your best bet to find a copy