Antenna selection advice?

[lumberjack_jeff]

I currently have a WE826 with EM7455 using T-Mobile. I am attached to a tower 8.5 miles away, with a couple of hills (and forests) between. I am using two homemade yagis about 20' off the ground. I currently get about 3mb up and 3mb down, which doesn't sound like much, but it's about 3-4x the download speed and 10x the upload speed that I get from the nasty buggers who sell me "dsl broadband" for $90 per month. Grr.

At!gstatus returns:

at!gstatus?
!GSTATUS:
Current Time: 526499 Temperature: 42
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B12 LTE bw: 5 MHz
LTE Rx chan: 5035 LTE Tx chan: 23035
LTE CA state: ACTIVE LTE Scell band:B2
LTE Scell bw:15 MHz LTE Scell chan:1125
EMM state: Registered Normal Service
RRC state: RRC Connected
IMS reg state: No Srv

PCC RxM RSSI: -90 RSRP (dBm): -115
PCC RxD RSSI: -93 RSRP (dBm): -118
SCC RxM RSSI: -93 RSRP (dBm): -126
SCC RxD RSSI: -94 RSRP (dBm): -140
Tx Power: 23 TAC: 2C5D (11357)
RSRQ (dB): -13.8 Cell ID: 015EE517 (22996247)
SINR (dB): 1.6

Attached is my terrain profile to the only tower remotely accessible to me. I can rotate my yagi array and make minimal difference, which stands to reason since I don't have LOS.
What omnidirectional antenna stands the best chance to improve upon what I have?

[Didneywhorl]

You will likely do best with omnis, though in this case if you still use directionals, a pair (or 2x2 MIMO single) flat panel directionals may work best. I think in your case a pair of 6+dbi omni-directional antennas will be your best bet. The higher the gain the better, as your signal numbers are low. You also have noise which may be from signals bouncing all around.
thewirelesshaven.com has a few to select from. There is a 2x2 MIMO omni on there, but it may need modification, as its made for putting a modem/router inside. Creativity!

[gscheb]

Hello,
What are homemade yagis?
Where are you and the tower on the profile pic?

[lumberjack_jeff]

Yagi antennae similar to this
http://bcbj.org/antennae/lte_yagi_diy.htm

I am on the far left, the cell tower is on the right. I would need roughly a 100' tower to clear the intervening hills.