Almost all of the Keurigs and other K-Cup brewers will dispense just hot water, you just press the brew button without a K-cup in the brewer. This is a reusable K-cup for using your own coffee.
Some other things to consider, is cup sizes and water capacity. Most brewers have more options on how much water to dispense for a cup of coffee. Which is handy when you want to make smaller or larger cups of coffee. Along with that, some have larger hoppers that hold water before it gets heated for making a beverage. The only real benefit of a large water tank is you don't have to fill it as often. If your boyfriend is only a light coffee drinker, the tank size wouldn't matter too much as it wouldn't get drained that often anyway.
All that being said, This is probably the least expensive one, only does 8 ounce cups, only holds enough water for one cup.
Something like This is your typical Keurig, 3 cup sizes (6,8,10 oz), 48 oz water reservoir
Personally, I have a model very similar to This one except I bought it from Costco. You can set it to automatically turn on and off in the morning on a timer, 5 cup sizes (4,6,8,10,12 oz) and a 72 ounce reservoir.
I would recommend looking at Costco, Bed Bath and Beyond, Target, etc. because you occasionally run into some deals. Good Luck.
For a single cup brewing and loose tea I like my refillable K cup.