Hello Saku,
I've casually talked with other people, and it seems I'm not really alone here. My dream box would be 96xSFP + 2xQSFP28, with pretty much full edge features (BGP, LDP, ISIS, +1M FIB, +5M RIB, per-interface VLANs, ipfix or sflow, at least per-port QoS with shaper, martini pseudowires).
I'd go with a Nokia/ALu 7750. Two 48x1G IMM, or 5x m20-1gb-xp-sfp MDA + 3 IOM3-XP, and 100G IMMs (1 or 2 CFP ports - no idea about qsfp28 options though) with SF/CPM5. This would fit in a SR7. Not sure about the smaller models (-c or -a series). The 7450 might be an option too, but I don't know this hardware. RIB size is 20M iirc (shared between all af) and fib size 3 or 5M depending of the card. SR-OS is weird when you're used to ios or junos, but in the end the cli is very efficient and quite enjoyable actually. HTH, pierre