For relatively small quantities of bulk aging wine, it is very hard to beat Sanke type beer kegs. Most are 15.5 gallons with a few others that are 5.2, 7.6 and 50L (13.2 gal). They will be ideal for "lighter reds" though lighter can refer to flavor, color or variety.
You need to pull out the spear in the center, then use them like 15.5 gallon carboys. They are excellent for aging wine. They are unbreakable, air and light tight, have good handles and easy to sanitize.
You can use a stopper in the top or adapt the tops to tri-clamp sanitary fittings. I have posted before on how to do that.
As to sources-your local Craigs list will almost always have them-I have paid as little as $15 for one and as much as $50. In the end, they are about the least expensive aging vessels you can use.
If you want to get fancy and pay a bit more, TCW in Napa has brand new ones with a sanitary fitting welded on top in place of the sanke fitting. THey are a about $125 or so, still a pretty good deal. I will likely transition to these over time.
I also age in Intellitanks. They hold 15 gallons and are super convenient to use. Unlike a keg, they have a top and a bottom spout and can be adapted to all sorts of chores in the garage winery. They are more expensive than Craigslist kegs, but they also are more flexible.
Here is 60 gallons of wine (actually there are also 3 carboys hidden there so more like 75 gallons) in 2 intellitanks and 2 stainless barrels, all in a small closet.