Help with gas furnace and AC upgrade options

I'm doing a major renovation on the house which is in the mid-Atlantic region Climate Zone 4A. The project includes a replacement of the HVAC units. The general contractor had included in his proposal the following:

Furnace: Carrier Infinity two-stage 59TN6
AC: Carrier Performance single stage 24ACC6

I've asked him to provide me with incremental cost for potential upgrades to the two units. Here's what he sent me:

Furnace:
Carrier Infinity modulating 59MN7 -> +$2,000

AC:
Option 1: Carrier Infinity single stage 24ANB6 -> +$2,000
Option 2: Carrier Infinity two stage 24ANB7 -> +$3,400
Option 3: Carrier Infinity five stage 24VNA9 -> +$3,700
Option 4: Carrier Infinity variable speed 24VNA0 -> $6,300

I'd like to spend no more than $4k extra on top of the current estimate. Based on that budget there are three configurations I am considering:

Configuration 1 - Upgrade AC to Infinity series: 2-stage furnace 59TN6 + 1-stage AC 24ANB6 (+$2k)

Configuration 2 - Upgrade AC to 5-stage: 2-stage furnace 59TN6 + 5-stage AC 24VNA9 (+$3.7)

Configuration 3 - Upgrade furnace and AC: modulating furnace 59MN7 + 1-stage AC 24ANB6 (+4k)

source https://hvac-talk.com/vbb/showthread.php?2226172-Help-with-gas-furnace-and-AC-upgrade-options&goto=newpost