If you are looking to buff up the list from rising powers guardian, hunter and soulstone miner all make great options for ramos.
Large spiders from my exp are not bad for 5 points however in jumping up to close double the cost they lose what makes the smaller spiders so great for ramos. They are no longer so cheep to make them easy to say hey lets just blow them up. Rare means you cant just spam them like little spiders. Unfortuently they are only have a little better stats, dont add any thing new that makes them stand out and no voltron tricks.
Guardian next to ramos basicly just makes him a rock. He was never fast and this guy wont help it. What it does do it make it so many crews are compleatly ineffective when trying to take him out. He makes a great tool for some missions. This is a model you need to look at the mission and decide if you want him.
Hunters add some great mobility and some lure ability to his crew. That being said dont let them get to far ahead of the crew or they will die.
Soulstone miners are a great addition for ramos. They can become invincible when needed and have great mobility. As long as you plan ahead they can be very nice for some mission objectives. Others they suck for but you will know that before you take them so plan acordingly. They can also dish out some nice damage if your willing to burn a soulstone. Like I said with the guardian this is another model you need to look at the mission and decide if its the tool for the job.