Yeah, Mupariwa - who's been in and out of the team for some time - should get a fairly permanent role now. He is a ready made replacement in more ways than one.
There is his bowling, which speed wise is similar, probably a bit slower:
Gary Brent (max 120 kmh · avg 110 kmh)
Brent has lost a lot of the pace he had a decade ago, in some part due to injury. Now his specialty is a nagging line and length, as he demonstrated against Australia in the Twenty20 World Cup, but if the pitch doesn't suit him he can be exposed for a lack of variation. Generally, Brent also opens the bowling, but if a quicker option is available, such as Christopher Mpofu or Tawanda Mupariwa, he will be first change. He has an interesting slower ball, despite a massive grant during the delivery it can go as slow as 90 kmh, perhaps deceiving some batsmen.
Tawanda Mupariwa (max 110 kmh · avg 100 kmh)
A bowler in the same mould as Gary Brent, Mupariwa's speed is surprisingly a touch slower, with most deliveries in the high 90's.
Let's not forget that Mupariwa is still very young, and with the right coaching should be able to bowl much faster, unlike Brent who as he grew older was only going to lose pace.
They both rely more on nagging line and length than any pace or swing. Mupariwa has a decent off-cutter I believe, which wouldn't be surprising. When you've got no pace, you have to rely a lot on variation.
Mupariwa's batting has become decent in recent years. Gary Brent is a solid batsman, and could bat as high as the lower middle order (just thinking back to his 59 against South Africa). Mupariwa has shown he is no bunny (33[?] against Bangladesh in the famous last ball six match, plus some decent returns in this Logan Cup)... certainly, Mupariwa should be averaging somewhere between 10 and 15 with the bat in ODI's.
There are some other options, Taurai Muzarabani - which none of us, bar zimdan maybe, have seen play. Ed Rainsford of course, if we are looking for someone with a bit of real pace and the team management decide to do away with the slowish medium pacers. As you say, Mpofu is a possibility, but I'm of the belief that the selectors would only select him on a pitch suited to quick bowlers, maybe a pitch with a bit of bounce on it. He wouldn't really be a replacement for Gary Brent, rather Mpofu would be selected in his own right, because the conditions suit
him. Then there are the spinners, which we have an abundance of - Graeme Cremer, Timycen Maruma, Tafadzwa Kamungozi... all options. But with Ray Price and Prosper Utseya in the same team, 3 spinners is unlikely.
I think Tawanda Mupariwa being his permanent replacement would be a good bet at the moment.