You probably want a package system that will take care of showers, toilet, and everything in the basement. You may want to put your washer into it also.
There is a check valve to prevent backflow, and if you flush a diaper down the drain it will probably plug up. You shouldn't need a grinder pump which is much more expensive.
Your basement won't flood if it fails if you stop putting water into it. You could easily hook up a loud alarm to go off if it fails.
Yes, there is a nasty pit to open up if you have to replace the pump, but it is a "lift out" job, not a crawl in the pit job.
I like to find out what is available so I can negotiate with the plumber from a base of knowledge. You can get some idea by looking at www.grainger.com and doing some product searches (or if you can get a Grainger catalog). When you get to their site, you can do a keyword search on simplex sewage system package and you will get bunch of them to look at. Click on the catalog number by the picture to get the specs.
There are also some that don't show up in the search above. Do another search on dayton sewage system .
I would probably pick something like the Stock No 5YU15 or the 3XA92 or the 3XA93. Others may be similar and I haven't looked at all of them.
One of the critical things is that you get enough flow (GPM) and head (ft) to overcome the rise to the point where it dumps into your gravity system. Assuming you are pumping up one floor level, I would get something that has at least 50 GPM at 15 ft of head. Flow is especially important if you put the washer into it.