Is this even possible? I have also purchased a Rolls MB15b converter. I'm very new to this and never realized how confusing it can be!

I paid very little for the amp so maybe I'm better off doing something different.

Thanks in advance for any help.

is this for yourself or do you do this professionally? How did you come up with this combo?

1) I'm going to take a good guess, you are a consumer.

2) Yes it is possible. Very easy in fact for an installer. There is nothing about your system that is out of the ordinary for an outdoor landscape system. And should be a standard install as such.
Of course the terrain in which the system is installed, will determine just how easy or difficult the final outcome will be. A flat, soft earth yard, with short distances would be quick & easy. An uneven rocky area with long distances could take over a day to install (digging, trenching, concealing, etc.).

3) Yes for a consumer who is also not an enthusiast (and mechanically inclined), it can be very confusing. I would STRONGLY suggest you hire a pro. This is NOT a simple thing as installing some LED lights for you rear patio. If you want it done right, you need to have someone who knows how to install these systems - that means proper placement, installation, and adjustment.
3a) Depending on where you live, finding an installer could be difficult. Like finding any contractor, there are plenty of idiots that have no clue what they are really doing as well. Of course they will tell you they can do it with no problem - get references!
3b) An electrician is NOT a f^ audio/video installer! I want to express that because for some reason the average consumer has this insane idea electricians can install electronics 'properly'. Maybe because the similarity in names? It doesn't mean you can't find an electrician that also is good at audio/video stuff, but in my experience that is a very rare bird (a flying unicorn).

Hope that helps.

This might be might lucky day because I see you're in South Georgia. I live in Savannah. Are you close enough to Savannah to be interested in doing this?

Oh...
I am right here at Hinesville/Ft. Stewart, so yes you are in my area. I'll PM you my contact info and we can talk about what you want to have done.

when I saw Savannah I though, sand, easy, then I thought, tree roots! LOL!

When you get far inland from the coast, we have GA red clay. That is a nightmare to trench. But don't see a lot of that near the coast.
We have a lot of old plantation Oak trees. Roots from those can certainly be a pain.
But for the most part the soil digs easy here near the coast, with no rocks. Good growing soil. But also very conductive, lighting strikes here are very damaging. And we get a lot.