I had a Bosch Model 1375A hand grinder for years before it finally bit the bullet and I replaced it with a DeWalt. Unless you're doing a lot of heavy grinding of steel, I'm thinking that a hand grinder would be a better choice than an angle grinder. It's smaller and lighter, and that means you can hold it in one hand, and that makes it more convenient to use where you want to grind or cut something small enough to hold in the other hand.
Here are some things I found important:
1. Try to get a hand grinder with a 5/8" X 11 tpi arbor. The reason why is that many rotary brushes will require this thread to mount on a hand grinder:
2. The place to find masonary or metal cutting blades or rotary brushes rated at 12,000 rpm (which is typical of what a hand grinder will spin at) is at welding supply stores.
Generally you'll find that cutting wheels meant for metal will be made of aluminum oxide, whereas those meant for cutting masonary will be made of silicon carbide. The reason for this is that the two abrasives work differently, and that results in each one being better suited for cutting a different kind of material.
Masonary is softer than steel, so the harder and more expensive abrasive (silicon carbide) will last longer cutting a softer material (masonary) than cutting a harder material (steel). You CAN cut metal with a silicon carbide blade, but the abrasive grains will just get dull faster, resulting in poorer performance.
Aluminum oxide is a softer and less expensive abrasive, but when aluminum oxide crystals break, they break to form sharp edges, and that continuous renewal of the cutting surface results in better cutting performance in hard materials like steel. That's because it takes a hard material to break the softer aluminum oxide grains.
Again, you CAN cut a softer material with aluminum oxide, but unless the aluminum grains actually break to form new sharp edges, then grains will just dull and cutting performance will decline.
So, silicone carbide works better and lasts longer when used to cut soft materials cuz it's harder, and aluminum oxide works better and lasts longer when used to cut hard materials because it breaks, forming new sharp cutting edges.
3. Whenever using a wire brush for cleaning, ALWAYS wear eye protection (even if it's your prescription eye glasses) and also wear heavier clothing. That's cuz the brush can let go of wires, and at 12,000 rpm those wires will fly right into your skin. I've had to pull steel wires out of the skin on my shins even when wearing blue jeans. If they'll go through blue jean denim and stick into my skin, then they'll go into an unprotected eye no problem at all. This isn't just one of these "cover my a$$ warnings" to protect the manufacturer. Whenever you use a rotary brush on a hand grinder, keep your face and especially your eyes out of the trajectory of a flying wire.