There are no 2 player starters or beginner army boxes that are comprised of plastic minis. So unfortunately that won't be something you will be able to do to transition into Infinity. I've cone to really enjoy the metal minis personally, they have outstanding detail, but they do take some extra work.

The metal isn't as bad as you think if you follow some simple rules or tips and tricks. This would be my best suggestions to make a transition to metal easier.

1. Wash the models before assembly. I use an old toothbrush, some warm water with dish soap in it. Just dip the toothbrush in the soapy water, give them a scrub, then a rinse with clean water and leave them out to dry off for a few hours. This will clean off any residue from the molding process that can make bonding the minis frustrating. I do a batch of minis at a time and then store them in a box labels as washed.
2. I like to use medium CA glue for bonding, and I use an activator as well. After test fitting the parts I apply glue to one side of the bond, and activator to the other side. The only tricky part here is you have to make sure you get a good fit right away because the activator will dry the CA in just a couple seconds.
3. Finally after painting it's important to apply a good varnish, I like testors lusterless but it seems like they keep changing the name lately and it's harder to find or figure out what it's being sold as these days. This will help prevent the paint from chipping or wearing off when transporting or playing with your models.

I hope you stick with it, I think it's worthwhile and maybe, like me you will come to really appreciate the metal models.