Mango and Mimi is right about the wheel sizes
I personally think a detolf is great for a Syrian - there are pros and cons to lack of height (less fall risks) and although it isn't quite as deep as usually thought of, I think the size of it makes up for that and the issue of fitting a larger wheel in is the only one really and there are ways round that.
Many people have gone for a set up with the wheel at one end in lower substrate and fenced off with higher substrate beyond it - or even with the sectioned off wheel and as a sand area instead of a sand bath. You would also have spacing for a flying saucer as well which would be a bonus.
Now this is a theory - not tried out - but if you drillled a hole in the end of the detolf it may be possible to mount the Silent Runner through the hole using the cage attachment plates. When it's off the stand it is only about 30cm tall. What I am not sure about is whether the bolt is long enough to allow for the depth of the detolf panel but it would be possible to just get a longer bolt. I have seen a wheel mounted to a detolf (ie screwed to the end) in this way.
I believe it was done with a Wood Karlie wheel off it's stand. Alternatively an 11" wodent wheel would be fine. There is so much space in the rest of the detolf that there is plenty of space for deeper bedding elsewhere and a lot of scope for enrichment of set up.
Most people make two standard lids that sit on the bars - it's the easiest option I think. Erin's Hamsters has a tutorial although some people have said the measurements aren't that correct so best to measure for yourself. Some of it depends on how wide the strips of wood are as to what lengths of wood you need.
So for example of the internal length of the detolf measured 160cm (I dont know, just guessing) you would need 2 x 80 cm long lids - less a mmm or 2 to allow for them to fit in comfortably. So you would need four lengths of wood a fraction under 80cm long. To get the size of the smaller end pieces of wood you would then need the internal depth of the detolf, less the width of the longer pieces of wood. So if the detolf measures 36cm internally (again guessing there) and your long pieces of wood are 10 cm wide and there are two of them then you'd need to take 20cm off 36 and only need a piece of wood 16cm long for the ends - to fit between the two long pieces.
To join the wood together you can buy little metal angle pieces that just screw in so you just need a screwdriver. The mesh you can usually get cut to size in the hardware store and use a standard stapler (a largish one probably but doesn't have to be ultra large) to staple the mesh to the wood.
Unless you have a very large syrian I would just go with a senior wodent wheel which will fit comfortably (it's about 31 cm tall - cant remember exactly). They can move about a bit on their stand so putting something like a heavy ceramic tile on the sand would help and then a thin layer of substrate or sand to cover the wheel stand. A medium bendy bridge or two on their sides can make a fence about 20cm tall beyond which you can have deeper substrate.