I have a few of the Metaloid 5Nii which is the old name but basically the same version of the Cavalla. I use it as a jigging and live bait reel but It should work just fine for trolling. They aren't quite as smooth as my Avets or Shimanos, but they are a quality reel that can take the abuse.

 

Penn FTH25NLD2LH. This is 2spd, if your happy with single speed drop the “2” from the part number and save about $75

The Penn Squall in 30 size is another option, slightly cheaper.

 

The fathom 2 speeds are nice reels for the price. In your hand the 30 doesn’t feel too much bigger so if you need more line for halibut, you might look at those.

I got mine from Charkbait and they put 300 yards of their braid on with purchase so that saves you some money.

Penn updated the fathom line a few years ago and then was slow to getting them out in stores.

 

The single-speed Fathom was my first choice, but I can't find them anywhere ... except on eBay from UK vendors.

 

I use 2 left hand retrieve Gen 1 Avet MXL's for trolling and like them. They do need to have the pinion bearing replaced every 2-4 seasons. Easy to do yourself. Might be something that has been fixed in the Gen 2

The 5N Cavalla (I have the metaloid and love it) seems a little small and more of a jigging reel. I'm sure it would work just fine for trolling. Looks like price goes up quite a bit for the bigger sizes

 

I have several of the Avet MXL 2 speed raptors and a couple of the Torium 16’s. I prefer the Avets over the Toriums but they both work well for trolling.

 

Big fan of the penn fathom 2 spds. Have 8 of them and never an issue, from 25-40's. They used to have sales on them around Black Friday time but that won't do you any good for this summer. Haven't gotten the new versions yet.