Welcome and congrats
This question is probably better in another subforum, but I'm sure the appropriate mod will come move it where you can get better answers.
My advice is to first of all talk to all of them. Get an idea of what their vision is for the novel. If the romance agent wants you to make huge changes, it might not make sense to make those changes for your genre (I've had this problem, lol). Also, you want to consider if the romance agent is going to have contacts to editors that publish your genre.
For all of them, see who you click with, and see what revisions they want and if you're okay with those. Get a feel for how they view you and your book and your future writing career. If your next book is going to be a thriller and they don't handle thrillers, that might be worth considering.
I'm a little wary of someone offering rep without reading the full novel. First of all, how can the agent know that your novel ends as well as it begins? Many fall apart at the end. How can they give you an accurate view of what you might have to change or know where they'd be able to send the novel?
There are good things about experienced agents and good things about new agents, especially those with experienced agencies. Experienced agents have great relationships with lots of publishers, but you might be a small fish in a big pond, and they might ignore you for bigger clients. Newer agents can focus on their clients, since they have fewer of them, but they might be lacking the connections to the publishers.
Without knowing the specific agents or agencies, I suggest checking out the Bewares, Recs, and Background Checks forum and searching for those agents. You'll find lots of information about them there (most likely). But definitely don't make a decision until you talk with them and get a feel for who you click with, whose vision is in line with the book, and who has a plan for the book and your future writing career.
ETA: Crossposted with JVC
