If you read the checkpoint product documents it quickly becomes confusing as to what hardware provides which features. Here is something that sums up all the differences (& cost) at a quick glance:
This document describes how the you can purchase the software only solution and what restrictions you have to keep in mind:
In many cases, a license bundle containing the management solution as well as one firewall is purchased. You can also buy a management solution (CPSM, mandatory) and the needed licenses for the Security Gateway(s). Be sure to order the correct size of CPSM! Additionally, you can obtain licenses for additional Software Blades which offer different security enhancements.
| SG100, SG200, SG400, SG800 and SG1200 series are designed to utilize 1, 2, 4, 8 and 12 cores respectively.
| SG100 series is limited to 50 users. SG200 series is limited to 500 users. SG203U pre-defined systems, SG400, SG800 and SG1200 series are unlimited.
| SM200, SM300, SM1000, SM2500, SMU000 are licensed to manage 2, 3, 10, 25 and unlimited gateways respectively.
|License is per number of managed gateways.|
Our requirements are SG203U (2 core, unlimited users) + SM200 (manage 2 gateways) it looks like we cannot buy them individually. The closest I can find is CPSG-P203-CPSM-P303 which is a 500 user limited license.