Should i stop collecting imperial guard?

I collect warhammer 40,000 and i have three armies,chaos,tyranids and imperial guard. For chaos and tyranid i got a small army with 1 HQ and 2 troop choices and then would add to it as i started a new one. This worked fine with chaos and tyranids until i got to imperial guard. It is taking me ages to get teh basic army as i didnt realise that you cant have cadian shock troops in a seprate squad, only in a platoon. This means that i am gonna have to get another command squad, another cadian shock troops. Also i dont have the codex (i got all of the imperial guard info from my freinds codex, but i only had a quick look) So could anyone recomend a good troop choice while i save up for the codex plz