They are quite different so it depends largely on where your interests lie. (I have both and they complement each other)
The ALPY is the natural successor to the Star Analyser and is an excellent low resolution instrument giving a similar spectral range and sensitivity but at typically ~4x the resolution and with the added advantage of being able to record extended objects. It is very stable and generally needs no ongoing adjustment once set up. It is best matched to a fast focal ratio of around f5-6 which can be an advantage or disadvantage (You need to use a focal reducer with SCT which introduces chromatic aberration) If going for the ALPY get the core module and guider as a minimum. The calibration module is nice to have but there are alternative solutions
Although you can use the LHIRES at low resolution the ALPY works better. The LHIRES is really for higher resolution work looking at the shape of individual line profiles on bright targets which is what it was designed for and is still the highest resolution spectrograph around for the amateur. I find it is rather like a racing car in comparison to the ALPY in that it needs frequent tuning to keep it performing well. It needs a focal ratio of around f10 so is well matched to typical SCT
Other options are 3D printed self build eg the LowSpec or currently being developed, the very interesting all reflective design UVEX which gives good performance over a wide spectral range. Both can be run at different resolutions. I will add the links to these if you are interested
EDIT links added
As always, I think Robin has given excellent advice. However, I think there is a relatively large animal in the room that hasn't been addressed: an observatory. When I went to the spectroscopy conference in New Mexico this year Francois Cochard from Shelyak asked how many people present had an observatory and more than 90% of the hands went up (not mine). I thought it was amusing at the time but I've come to realize it's no coincidence.
I have an Alpy and I love it and I would use it much more often if I could, but I have found that given kids, work and weather that opportunities are infrequent to take everything out, cool down the camera and telescope, polar align, calibrate PhD, center and acquire spectra of both the target and a reference star. An observatory would greatly expedite this process and I highly recommend one.
I think your current setup is quite interesting. Do you use the flip mirror on the Vixen? I found that the temptation with the Alpy was to go for greater aperture and light gathering capability. This increased time and effort to ensure good guiding. Perhaps by keeping the telescope small, you could stick with your EQ-5 mount, which I presume you find easy to polar align and guide with.
For now, my Alpy and 8" scope wait for better weather and I am often observing during a break in the clouds with a 55mm refractor, a Star Analyzer 100 and CMOS camera. I'll post on another thread so you can see what that looks like.