Hi Matt,
If APRS messaging for spots is a must have then,
a bit easier.
From Yaesu the FT2DR and FT3DR (FT1DR is not in sale anymore) have APRS onboard including messageing and position beacons. VX-8DR needs an external GPS module for tracking (as far as I know).
User-interface is Yaesu-typical a bit “sub-structured” aka confuse.
I have the FT1 and got used to it.
From ICOM the ID-51E PLUS2 is the only option at them moment for new devices as far as I know.
From Kenwood the TH-D72A and TH-D74E have full APRS compatibility but a bit on the costly side.
Apart from handhelds there are other options. I.e. Bluetooth box that acts as modem and in combination with an Android phone (and APRSDroid) can send and receive APRS.
http://www.mobilinkd.com/tnc2/
Or get a standalone APRS tracker if you don’t need/want a handheld. Matt @OE6FEG has one that can be programmed and transmits the spot on keypress when the summit is reached
See his report here: Pico APRS for APRS2SOTA
The AnyTone AT-D878UV can in analog APRS mode only do position beacons but no messaging. So spots are not possible (I see no info in the firmware changelog that would indicate that this has changed recently).
Theoretically you can also run ARPS via HF with a 300 baud rate. I have not tested that so no clue how well the reception is.
On 2m 144.800 MHz it works pretty good from the summit at least here in OE.
73 Joe