There are a lot of choices that could fit the bill for you. There's something to be said for using a system with similar screens and buttons as what you're familiar with. If you're using a
Garmin chartplotter, it will likely be a quicker
learning curve to use a
Garmin radar. We had a 740s system on our earlier
boat that worked very well. I would also second Dockhead's recommendation to consider an MFD both for space and for the convenience of some of the overlays. As you leave US waters, you'll want to be sure that the
charts on your
chartplotter position you accurately. The
radar overlay can show you offset errors and keep you out of dangerous situations.
You mention cost as an issue, but don't give a
budget. If dollars are a dominant issue, consider
buying a used system. With all the recent interest in pulse systems, there are often options on eBay that were state of the art just a few years ago.