If you can easily afford it and have the space, get your dream rig. I own a fairly large amp collection. Here are the Mesa amps I have: D180, 400, 400+, Buster, Strategy Eight:88, Titan V12, M9 Carbine.
For the most part I stopped gigging on bass around 2008. I did a few years after that as an audio tech and probably did 5 gigs on bass. In 2011 I started collecting amps. They are my guilty pleasure and they serve little practical purpose other than to give me joy.
If the church is set up for IEMs and has a good audio tech, that's the way I would go. Halls of worship are often big boomy environments, so it best to keep the stage volume low; not that this always happens in worship groups.
If you want to use an amp and the stage volume is relatively low, I would suggest a small rig that can be tilted back in front of you. I have an old GK 700RB/112 combo. It's bit on the large side for this purpose; about the same size as a Subway 115.
Keeping it small may not be reasonable if the group plays loud. A Mesa D350 with a Subway 115 is relatively small and will be capable of moderate volume. The Subway 112 is a bit smaller and you only loose about 1dB of Sensitivity. If you add a matching cab with the D350 you get +6dB. Using an 800W Subway amp with a single cab will give you +3.5dB over the D350. FYI the Boogie channel in the TT800 was modeled on the 400 and 400+

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Calculated SPL (estimates):
- D350 with one Subway 112 = ~120dB
- D350 with two Subway 112 = ~126dB
- D350 with one Subway 115 = ~121dB
- D350 with two Subway 115 = ~127dB
- 800 with one Subway 112 = ~ 123.5dB
- 800 with two Subway 112 = ~ 129.5dB
- 800 with one Subway 115 = ~ 124.5dB
- 800 with two Subway 115 + ~ 130.5dB